The Pilgrims appeared to be heading to defeat at the Jakemans Community Stadium following Tom Platt's headed own goal in the 10th minute following a trademark long Doug Tharme throw-in.

However, United rallied despite numerous stoppages and levelled when Shiels headed home Joe Leesley's cross with a minute of normal time remaining.

The Pilgrims had already survived a let-off when Jack Doyle's free-kick hit the underside of the crossbar and ex-United striker Jordan Archer headed over an unguarded net.

Port took a 10th minute lead when PLATT inadvertently diverted Tharme's torpedo-like throw beyond Marcus Dewhurst, who was attempting to punch clear in the process.

United almost levelled when Connor Dimaio rattled the crossbar midway through the first half.

The impressive Tyler Walton - and Archer on the end of Charlie Munro's cross - had chances to kill the contest for the visitors, but fired off target.

Boston took full advantage in the 89th minute when SHIELS saw his header squirm through the dive of keeper Cameron Mason, following Leesley's quality ball into the box.

Boston (4-3-3): Marcus Dewhurst; Matt Tootle, Luke Shiels, Scott Garner, Scott Duxbury; Connor Dimaio (Jay Rollins 62), Tom Platt, Shane Byrne; Fraser Preston (Jordan Preston 85), Danny Elliott, Joe Leesley. Subs (not used): Keenan Ferguson, Ben Sault, Peter Crook (gk).

Southport (3-5-2): Cameron Mason; Doug Tharme, Liam Edwards, Adam Anson; Charlie Oliver, Jack Bainbridge, Charlie Munro, Dylan Vassallo, Jack Doyle; Jordan Archer, Tyler Walton. Subs (not used): Russell Benjamin, Connor Woods, Isaac Buckley-Ricketts, Ryan Corrigan, Tony McMillan (gk).

Referee: Paul Brown.

Attendance: 1,552 (57 visitors).

PIC: Tim Hoff.